CN208383718U - A kind of fluorescence detecting system suitable for anaphylactic reaction tester - Google Patents
A kind of fluorescence detecting system suitable for anaphylactic reaction tester Download PDFInfo
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- CN208383718U CN208383718U CN201820942120.7U CN201820942120U CN208383718U CN 208383718 U CN208383718 U CN 208383718U CN 201820942120 U CN201820942120 U CN 201820942120U CN 208383718 U CN208383718 U CN 208383718U
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Abstract
The utility model relates to a kind of fluorescence detecting systems of suitable allergic reaction detector, its fluorescence detecting system includes optical subsystem and electricity subsystem, its electricity subsystem includes power circuit and photoelectric measurement subsystem, its photoelectric measurement subsystem includes uv excitation light intensity adjustment module, photoelectric current amplification module, MCU circuit and RS485 communication module, wherein its photoelectric current amplification module includes Current Voltage conversion and signal amplification circuit, high-pass filter and comparator circuit, low-pass filter and adc circuit, fluorescence signal after allergic reaction separates two paths of signals after Current Voltage conversion and signal amplification circuit amplification, enter the low-pass filter and adc circuit all the way, another way enters the high-pass filter and comparator circuit, to realize a wide range of continuous measurement of fluorescence.
Description
Technical field
The utility model belongs to medical instruments field, and in particular to a kind of fluorescence detection suitable for anaphylactic reaction tester
System.
Background technique
Anaphylactia is the most wide clinical immunization disease in a kind of influence face, is classified as the big non-infection of 21 century 4 by WHO
One of property disease (cardiovascular and cerebrovascular, tumour, obesity, allergy), the important pathogenic root of the major diseases such as allergy or asthma.Therefore
The diagnosis and treatment instrument for reinforcing anaphylactia has very important significance.
Allergic reaction test in, need to extract the blood sample of tested people cultivate anaphylactogen measurement reagent, and with
Different types of anaphylactogen is reacted, and determines anaphylactoid degree by the content of histamine in detection product.In group
In amine content measurement process, test fluid is handled by chemical reaction mechanism, is made wherein containing directly proportional to Histamine concentrations
Hyperfluorescence reactant.After fully understanding its excitation spectrum and emission spectrum, using fluorescence reaction mechanism, by generated fluorescence
The light intensity of reaction is accurately measured.Host computer is sent the data to, whether host computer is doubtful to this to patient by specific algorithm
Anaphylactogen allergy judges, and obtains allergic reaction quantitative data.For allergic reaction detecting instrument, fluorescence detection subsystem
It is its core.Currently, domestic there is no mature allergic reaction detecting instrument, invents one kind and be suitble to full-automatic allergic reaction
The fluorescence detecting system of tester generates certain light intensity exciting light, detection transmitting light intensity, large-range measuring in measurement process
Data conversion, and carried out data transmission according to certain communication protocol with host computer and receive the order of host computer and parameter is matched
It sets, in order to guarantee measurement accuracy, other than needing jamproof overall plan, it is also necessary to well-designed measuring circuit and power supply
Circuit.
Utility model content
The purpose of this utility model is that being directed to the deficiency of currently available technology, at least provide the following technical solutions:
A kind of fluorescence detecting system suitable for anaphylactic reaction tester comprising: optical subsystem and electricity subsystem,
The optical subsystem includes ultraviolet laser light source and photomultiplier tube, and the electricity subsystem includes power circuit and photoelectric measuring
Quantized system, the photoelectric measurement subsystem include uv excitation light intensity adjustment module, photoelectric current amplification module, MCU circuit
And RS485 communication module, the uv excitation light intensity adjustment module output end is connect with the ultraviolet laser light source, defeated
Entering end and the MCU circuit connection, the photoelectric current amplification module is connect with the MCU circuit and the photomultiplier tube,
The RS485 communication module and the MCU circuit connection, the power circuit are whole system power supply, wherein the photoelectric current
Amplification module includes high-pass filter and comparator circuit, low-pass filter and adc circuit, the fluorescence signal warp after allergic reaction
Two paths of signals is separated after amplification, all the way enter the low-pass filter and adc circuit, another way enter the high-pass filter with
Comparator circuit, to realize a wide range of continuous measurement of fluorescence.
Further, the uv excitation light intensity adjustment module includes ultraviolet DAC and its isolation circuit, adjustable current source
Circuit, the ultraviolet DAC and its isolation circuit and the MCU circuit connection, the output end of the ultraviolet DAC with it is described adjustable
Current source circuit connection, the forward adjustable current source circuit are connect with the ultraviolet laser light source.
Further, the photoelectric current amplification module includes that multiplier DAC and its isolation circuit, adjustable photomultiplier tube are high
It is piezoelectricity source circuit, Current Voltage conversion and signal amplification circuit, high-pass filter and comparator circuit, impulsive quarantine circuit, low
Bandpass filter and adc circuit, ADC interface and its isolation circuit, the multiplier DAC and its isolation circuit, impulsive quarantine circuit,
ADC interface and its isolation circuit respectively with the MCU circuit connection, the output end of the multiplier DAC and its isolation circuit with
The adjustable photomultiplier tube high-voltage power circuit connection, the adjustable photomultiplier tube high-voltage power circuit output end with it is described
Photomultiplier tube connection, the photomultiplier tube output end is converted with the Current Voltage and is connect with signal amplification circuit, described
Current Voltage conversion is electric with the high-pass filter and comparator circuit, low-pass filter and ADC respectively with signal amplification circuit
Road connection, the high-pass filter and comparator circuit and the impulsive quarantine circuit connection, the low-pass filter and ADC electricity
Road connection is connect with the ADC and its isolation circuit.
Further, in the electricity subsystem, the power circuit includes isolated buck transformer, rectifying and wave-filtering, DC/
DC conversion and LDO, to provide electric energy for whole system.Isolating transformer is used to provide power supply, power supply area for each region
Mutually not altogether.
Further, the power circuit is divided into 4 isolated power supply areas, and photoelectric multiplier power supply and photosignal are measured as
Analog power area 1, ultraviolet circuit part are analog power area 2, MCU circuit is digital power area 1, RS485 telecommunication circuit is several
Word power supply area 2.
Further, the analog power area 1 include the output of isolated buck transformer, rectifying and wave-filtering, DC/DC converter,
Negative supply charge pump DC/DC chip and LDO circuit.Acquisition+12V ,+4V and -4V voltage；
Further, the analog power area 2 includes the output of isolated buck transformer, rectifying and wave-filtering, DC/DC converter
And LDO.Acquisition+12V and+4V voltage；
Further, the digital power area 1 includes the output of isolated buck transformer, rectifying and wave-filtering, DC/DC converter
And LDO circuit.Acquisition+3.3V voltage；
Further, the digital power area 2 shares the output of isolated buck transformer, rectification filter with part number power supply 1
Wave and DC/DC converter use DC/DC again on this basis.The isolation output of realization+5V voltage.
Further, the RS485 communication interface and its isolation circuit using RS485 communication chip SP485 and number every
From device ADuM1301, the communication with host computer (such as PLC) is realized.MCU uses low-power chip STM32L433RCT6, and MCU is logical
Cross its On-Chip peripheral USART realize RS485 communication, by multiple On-Chip peripheral SPI interfaces be arranged ultraviolet laser operating current,
Photoelectric multiplier high-pressure work voltage is set, reads the ADC output valve in fluorescence current amplification circuit；MCU passes through impulsive quarantine
Circuit obtains photon pulse input, is counted by its on piece 32-bit counter, realizes photon counter function.
MCU gives allergic reaction measure setup ultraviolet light intensity by ultraviolet DAC and its isolation circuit, forward adjustable current source circuit.
After fluorescence signal after allergic reaction carries out the 1st grade of amplification by photoelectric multiplier, amplify by Current Voltage conversion with signal
After circuit carries out the 2nd grade of amplification, current-to-voltage convertor uses high input impedance, high bandwidth, low noise and low biased amplifier
OPA659, signal amplifier use high bandwidth amplifier OPA2690.When tested fluorescence intensity is larger, signal is that amplitude is larger
And lesser direct current signal is fluctuated, light intensity is directly proportional to amplitude；When tested fluorescence intensity is smaller, photon sparsely passes through photoelectricity
Multiplier tube, signal are each pulse of separation.Two paths of signals is separated after 2nd grade of amplification, is entered all the way suitable strong anaphylactoid
Low-pass filter and adc circuit, realize the level measurement of signal, another way enter be suitble to weak anaphylactoid high-pass filter with
Comparator circuit, the inside configuration MCU 32-bit calculator realizes the step-by-step counting measurement of signal, to realize that a wide range of allergy is anti-
The fluorescence detection answered.Configure the cutoff frequency f of low-pass filterLGreater than the cutoff frequency f of high-pass filterHSo that photon counting
Fluorescence detection method and fluorescence level detection method realize a wide range of continuous measurement.Back when using ADC measurement unstressed configuration reaction
Scape noise level, when formal fluorometric investigation, subtracts the ambient noise to improve measurement accuracy, while passing through setting comparison circuit
Reference voltage is 2 times of background noise level, and the essence of step-by-step counting is improved using the dynamic reference voltage proportional to noise
Degree and adaptability.
Analog power area 1 is by the output of isolated buck transformer, rectifying and wave-filtering, DC/DC converter (LMZ14201H), negative electricity
Source charge pump DC/DC chip TC7662B and LDO (LP38798 and TPS7A30) circuit composition, acquisition+12V ,+4V and -4V electricity
Pressure；Analog power area 2 is by the output of isolated buck transformer, rectifying and wave-filtering, DC/DC converter (LMZ14201H) and LDO
(LP38798) circuit forms, acquisition+12V and+4V voltage；Digital power area 1 by the output of isolated buck transformer, rectifying and wave-filtering,
DC/DC converter (LMZ14201H) and LDO (SPX1117) circuit composition, acquisition+3.3V voltage；Digital power area 2 and number
Power supply 1 shares the output of isolated buck transformer, rectifying and wave-filtering and DC/DC converter (LMZ14201H), adopts again on this basis
It is isolated with DC/DC (DCV010505P) realization+5V voltage and is exported.
The RS485 communication interface and its isolation circuit of the electricity subsystem of fluorescence detecting system use RS485 communication chip
SP485 and digital isolating device ADuM1301, realizes the communication with host computer (such as PLC).MCU uses low-power chip
STM32L433RCT6, MCU realize RS485 communication by its On-Chip peripheral USART, are set by multiple On-Chip peripheral SPI interfaces
Set ultraviolet laser operating current, setting photomultiplier tube high-pressure work voltage, read fluorescence current amplification circuit in ADC it is defeated
It is worth out；MCU obtains photon pulse input by impulsive quarantine circuit, is counted by its on piece 32-bit counter, realizes
Photon counter function.
MCU gives allergic reaction measure setup ultraviolet light intensity by ultraviolet DAC and its isolation circuit, forward adjustable current source circuit.
After fluorescence signal after allergic reaction carries out the 1st grade of amplification by photomultiplier tube, amplify by Current Voltage conversion with signal
After circuit carries out the 2nd grade of amplification, current-to-voltage convertor uses high input impedance, high bandwidth, low noise and low biased amplifier
OPA659, signal amplifier use high bandwidth amplifier OPA2690.When tested fluorescence intensity is larger, signal is that amplitude is larger
And lesser direct current signal is fluctuated, light intensity is directly proportional to amplitude；When tested fluorescence intensity is smaller, photon sparsely passes through photoelectricity
Multiplier tube, signal are each pulse of separation.Two paths of signals is separated after 2nd grade of amplification, is entered all the way suitable strong anaphylactoid
Low-pass filter and adc circuit, realize the level measurement of signal, another way enter be suitble to weak anaphylactoid high-pass filter with
Comparator circuit, the inside configuration MCU 32-bit calculator realizes the step-by-step counting measurement of signal, to realize that a wide range of allergy is anti-
The fluorescence detection answered.Configure the cutoff frequency f of low-pass filterLGreater than the cutoff frequency f of high-pass filterHSo that photon counting
The intersection region being applicable in while fluorescence detection method and fluorescence level detection method have larger is to realize continuous on a large scale survey
Amount.Background noise level when using ADC measurement unstressed configuration reaction, when formal fluorometric investigation, subtract the ambient noise to improve and survey
Accuracy of measurement, while by 2 times that the reference voltage of setting comparison circuit is background noise level, it is moved using proportional to noise
State reference voltage improves the precision and adaptability of step-by-step counting.
The adc circuit uses 24 ADS1246, includes and may be programmed amplification according to 2 times of 8 grades for being incremented by from 1 to 128 times
Device PGA is, it can be achieved that strong anaphylactoid wide scope measurement.Comparator uses high-speed comparator ADCMP601, and 10MHz may be implemented
Pulse processing.
The compatible existing other RS485 communication protocols of Allergic skin test instrument of the RS485 communication protocol of the fluorescence detecting system
View, so that only needing a RS485 network inside entire Allergic skin test instrument, new RS485 agreement is compatible with existing on the application layer
RS485 application layer protocol.
Compared with prior art, the utility model at least has the advantages that
(1) the photoelectric current amplification module of the utility model fluorescence detecting system includes Current Voltage conversion and signal amplification electricity
Road, high-pass filter and comparator circuit, low-pass filter and adc circuit, the fluorescence signal after allergic reaction is through Current Voltage
Conversion with signal amplification circuit amplification after separate two paths of signals, all the way enter the low-pass filter and adc circuit, another way into
Enter the high-pass filter and comparator circuit, to realize a wide range of continuous measurement of fluorescence.
(2) fluorescence detecting system of the utility model combined using isolated buck, switch and linear transform circuit and
Power supply switched-mode power supply mode come reduce interference and improve power-efficient；Using the adjustable uv excitation light of intensity and photomultiplier tube
Operating voltage can transfer to improve fluorescence detection range；It is combined using photon counting method and amplitude measurement method to realize that fluorescence is big
Range continuously measures, and the comparison voltage of photon counting method is adjusted by ambient noise, improves measurement accuracy, realizes glimmering
Exact value can be obtained in a wide range of one-shot measurement of light.
(3) power circuit of the fluorescence detecting system of the utility model is divided into 4 different zones, including " isolation drop
Pressure transformer+rectifying and wave-filtering+DC/DC conversion+LDO ", not only ensure that good Disturbance Rejection ability, but also reduce volume and power consumption.
(4) in the measurement process of the fluorescence detecting system of the utility model, adjustable excitation ultraviolet ray intensity and
The amplification factor of photomultiplier tube expands the measurement range to weak signal, while can be according to the automatic tune of power of measured signal
The size of PGA in ADC is saved, optimum measurement is realized, finally realizes a wide range of one-shot measurement of allergic reaction product concentration, it is existing
Having measurement method, often bigness scale and thin survey measure twice to realize, need to prepare 2 same samples, increase cost and reduce
Efficiency.
Detailed description of the invention
Fig. 1: the fluorescence detecting system structural schematic diagram suitable for allergic reaction detector of the utility model.
Fig. 2: the circuit construction of electric power schematic diagram of the utility model.
Fig. 3: the measurement method process for the fluorescence detecting system suitable for allergic reaction detector of the utility model
Figure.
Specific embodiment
The specific implementation of the utility model is described in detail with reference to the accompanying drawing.The utility model is suitable for allergy
The fluorescence detecting system structure of reaction detection instrument is as shown in Figure 1, the fluorescence detecting system includes optical subsystem and electricity
System.Optical subsystem includes that the ultraviolet laser light source, exciting light optical filter, sample flow being sequentially connected lead to pond, transmitting light
Optical filter and photomultiplier tube.The ultraviolet light that excitation light source issues can contain certain frequency band ultraviolet wavelength ingredient, be passed through
It can be reduced ultraviolet bandwidth after exciting light optical filter；Ingredient is many and diverse in sample, in the transmitting light after fluorescence reaction and is mixed with a variety of
The light wave of impurity obtains eventually entering into light for anaphylactoid histamine specific wavelength visible light after emitting light optical filter
Optical signal is changed into electric signal by electric multiplier tube.
The ultraviolet laser light source can be 365nm ultraviolet LED, and 365nm ultraviolet LED uses LTPL-C034UVH365；
Exciting light optical filter uses BP365-10K, narrow-band filtering effect needed for possessing the light source of suitable this system detection.Measure sample
Flow cell selects flowing quartz colorimetric utensil, and with two conduits of disengaging, 100 microlitres of volume, prepare liquid is examined by anaphylactogen before measuring
It surveys instrument control high-precision syringe pump to circulate pond, waste liquid is controlled after being measured and flows out to waste liquid pool.Transmitting light optical filter is adopted
Use BP445-10K；Photomultiplier tube uses R11558 end window type.Being mounted in designed closed measuring box with upper-part,
It completes to be mechanically fixed and prevent the relative movement between each component, and completely cuts off extraneous light pollution, improve measurement accuracy.
The power circuit of electricity subsystem is as shown in Fig. 2, converted 220V AC power source using isolated step-down transformer
Cheng Sanlu mutually isolated low-voltage alternating-current electricity output；It is defeated to obtain three road DC voltages after bridge rectifier and LC filtering for every road
Out.Three road low-voltage dc power supplies are converted into each analog- and digital- power supply in road needed for system by low voltage DC/DC, and DC/DC is used
The adjustable LMZ14201H of the good output of electromagnetic compatibility characteristic.
Wherein, the 1st tunnel after rectifying and wave-filtering output obtains 5V voltage output after LMZ14201H, is separated into two-way；One
Road obtains+3.3V output after low drop voltage voltage-stablizer SPX1117, is MCU circuit power as digital power 1；It is another
Isolated power supply chip DC V010505P is accessed on road, and+5V the output being isolated is RS485 communication interface as digital power 2
Part powers, and realization telecommunication circuit is isolated with MCU circuit.The 2nd tunnel after rectifying and wave-filtering output obtains after LMZ14201H
To 15V power supply, which obtains the analog power 1 of+12V by low pressure difference linear voltage regulator LP38798, as high voltage power supply mould
The working power of block CC228-09Y, output are used as photomultiplier tube operating voltage；15V power supply is obtained by LP38798 simultaneously
+ 4V analog power 2 obtains -4V analog power 3 ,+4V analog power 2 and -4V simulation electricity by TC7662B and TPS7A30
Positive-negative power of the source 3 as supply photosignal measurement part.The 3rd tunnel after rectifying and wave-filtering output obtains after LMZ14201H
To 6.5V power supply, it is divided into two-way, all the way through low pressure difference linear voltage regulator (LDO) LM2941, obtains the simulation electricity of more stable+6V
Source 4 powers for ultraviolet LED forward adjustable current source circuit；Another way obtains+4V voltage output through LP38798, as ultraviolet DAC's
Analog power, the output of DAC is for adjusting ultraviolet LED output electric current.
The MCU circuit of electricity subsystem uses low-power chip STM32L433RCT6, dominant frequency 80MHz, can good conformity
The requirement of photon counting frequency.The SPI interface and ultraviolet DAC and its isolation circuit, multiplier DAC that MCU passes through its On-Chip peripheral
And its isolation circuit, ADC interface and isolation circuit are connected, settable ultraviolet laser operating current, setting photomultiplier tube are high
It presses operating voltage and reads the ADC output valve in fluorescence current amplification circuit.MCU passes through the USART interface of its On-Chip peripheral
It is connected with RS485 communication and its isolation circuit, realizes RS485 communication.On piece 32-bit of the impulsive quarantine circuit connection to MCU
Counter is counted, and realizes photon counter function.
The RS485 communication interface and its isolation circuit of electricity subsystem are using RS485 communication chip SP485 and number isolation
Device ADuM1301 realizes the communication with host computer (such as PLC).Side VIA, VIB, VOC foot of ADuM1301 isolating device point
Not Jie Ru MCU USART2_DE (use GPIO pin), USART2_TX and USART2_RX pin, the other side VOA, VOB, VIC
Foot is respectively connected to RS485_DE (RS485_DE is connected with RERS485_RE), RS485_DI, RS485_RO foot of SP485.
In the ultraviolet DAC and its isolation circuit of electricity subsystem, ultraviolet DAC uses TLV5623 (8 single channel digital-to-analogues
Converter), output voltage is input to light intensity setting value of the forward adjustable current source circuit as ultraviolet LED.Due to the electricity of ultraviolet DAC
Source is analog power 2, and MCU power supply is digital power 1, and the two altogether, not joined isolation circuit.Using 1
The ON/OFF of TLV5623 and LM2941CT are connected respectively to after the output of SPI3 interface and the isolation of I/O of ADuM150N realization MCU
Switch.The reference voltage of ultraviolet DAC uses the stabilization+3V voltage that the REF3030 of analog power 2 is exported.The electricity of ultraviolet LED
Stream realizes the master of controllable constant current source circuit using the Darlington transistor that PNP triode 2SA2013 and NPN triode PMBT3904 is formed
Circuit, current measurement is used to be realized with the concatenated sampling resistor of ultraviolet LED, sampled voltage feedback to operational amplifier
(OPA2188) in reverse input end, and in-phase end connects the voltage output of ultraviolet DAC, which sets as ultraviolet LED electric current
Definite value, operational amplifier output connect driving tube base stage, form negative feedback closed loop circuit, realize the voltage output value pair of ultraviolet DAC
The control of ultraviolet LED electric current, MCU adjust the light intensity of ultraviolet LED by adjusting the voltage output of ultraviolet DAC.
In the Current Voltage conversion of electricity subsystem and signal amplification circuit, if Fig. 1 shows, the negative electricity of photomultiplier tube output
Signal is flowed, current-to-voltage converting circuit is first passed through, OPA659 (broadband, unity gain stable operational amplifier) is used and is connected into depth
Negative feedback type is spent, feedback resistance R takes 10k, then output voltage U=-I*R, obtains the positive voltage signal of amplification 10k multiple.It
Afterwards, signal amplification circuit is entered back into, the form of scaling circuit in the same direction is connected into using OPA2690, voltage signal is amplified to
The range properly measured, later amplified signal respectively enter simultaneously low-pass filter and adc circuit and high-pass filter with
The passband of comparator circuit, high-pass filter and low-pass filter has common region, to realize continuous measurement.
In the low-pass filter and adc circuit of electricity subsystem, low-pass filter constitutes passive filtering by RC circuit, cut-off
Frequency fLIt is equipped with by resistance and capacitance, makes fLGreater than the cutoff frequency f of high-pass filterH.ADC is used
ADS1246 (24 analog-digital converters) accesses AINP and AINN foot, reference voltage pin after the low-pass filtered device output of signal
REFP, REFN meet reference voltage+3V identical with multiplier DAC.Later, the digital output of signal level size connects to ADC
In mouth and isolation circuit.
In the multiplier DAC and its isolation circuit of electricity subsystem, multiplier DAC uses TLV5625 (8 binary channels numbers
Mode converter), first via output voltage OUTA is input to adjustable photomultiplier tube high-voltage power circuit as low voltage control side
Voltage given value.Since the power supply of multiplier DAC is analog power 1, and MCU power supply is digital power 1, and the two altogether, does not add
Isolation circuit is entered.It is similarly SPI communication, to save I/O mouthfuls, the SPI3 interface of MCU has been shared, using 2 ADuM152N realities
The I/O isolation of existing SPI interface and pulse input.The REF3030 that the reference power source of multiplier DAC uses analog power 1 is exported
Stabilization+3V voltage.
In the adjustable photomultiplier tube high-voltage power circuit of electricity subsystem, the output of multiplier DAC is through operational amplifier
The coordination electrode of OPA188 connection high-voltage power module CC228-09Y, controls the operating voltage of photomultiplier tube in 0~1000V
Between adjust.
In the ADC interface and isolation circuit of electricity subsystem, since the power supply of ADC is analog power 1, and MCU power supply is
Digital power 1, the two not altogether, therefore joined isolation circuit.It is shared with the multiplier DAC and its isolation circuit of electricity subsystem
SCLK, DIN, DOUT, RESET pin of 2 ADuM152N, ADS1246 be respectively connected to after being isolated MCU SPI3 interface and
In one I/O；DRDY, CS, STARTF of ADS1246 is connected after being isolated with three independent I/O of MCU.
In the high-pass filter and comparator circuit of electricity subsystem, high-pass filter constitutes passive filtering by CR circuit,
Cutoff frequency is equipped with by resistance and capacitance, makes fHLess than the cutoff frequency f of low-pass filterL.Comparator
Using ADCMP601, VP foot connects high-pass filter output, and VN foot is comparator reference voltage, by the multiplier DAC on total ground
Second tunnel exports OUTB and provides, background noise level when value is the unstressed configuration reaction measured before formally measuring using ADC
2 times, the precision and adaptability of step-by-step counting are improved using the dynamic reference voltage proportional to noise.Comparator output
Q foot accesses impulsive quarantine circuit, and HYS foot is that hysteresis controls pin, and by 470K resistance eutral grounding, hysteresis voltage about 10mV is arranged.
In the impulsive quarantine circuit of electricity subsystem, since pulse signal belongs to analog power 1, MCU belongs to digital power
1, the two altogether, not joined isolation circuit.Using 2 shared with the multiplier DAC and its isolation circuit of electricity subsystem
Two-way pulse input (from the point of view of the direction MCU) in ADuM152N supports pulse frequency to be up to 150MHz, meets in measurement
Photon counting requirement.Pulse connects the timer ETR foot inside MCU through the I/O pin of MCU, and is set as external clock source module
2, timer number of pulses is counted, to realize the measurement of unit time pulse number.
The measurement for the fluorescence detecting system suitable for allergic reaction detector below with reference to Fig. 3 to the utility model
Process is further described.
Step1, MCU electrification reset, program start to execute.
Step2 will be arranged multiplier DAC, ultraviolet DAC according to default value and export, is i.e. setting ultraviolet LED light intensity, multiplier
Operating voltage and comparator reference voltage value, wherein comparator reference voltage default value is that formal measurement is preceding to be measured using ADC
Unstressed configuration reaction when 2 times of background noise level；The sampling rate of ADC and the amplification factor of PGA are set, and complete ADC
Offset calibration and gain calibration；Complete step-by-step counting timer configuration, and configured RS485 messaging parameter so as to later
Good communication is kept with host computer.
Step3 waits RS485 to receive instruction, i.e. waiting host computer conveys instruction to control next task.
Step4, after receiving described instruction, i.e., according to the corresponding instruction of photoelectric measurement subsystem in the agreement of table 1,
Corresponding program branch is executed by corresponding.Wherein, when receiving host computer read states or reading data command, Step41 is executed, MCU will
Sending current state or newest data by RS485, current state includes two, i.e., " in measurement " or " measurement terminates ",
Its data is then the newest light intensity value measured.Measurement instruction is executed when receiving host computer, executes Step42, MCU executes one
Secondary measurement will open configured good step-by-step counting timer, opens ultraviolet LED and provides excitation light source, enabled ADC sampling, opens
Begin to measure；In measurement process, monitor signals in real time level is adjusted to ultraviolet LED light intensity and photomultiplier tube pipe work electricity
The PGA amplification factor of pressure and ADC, to cope with weak signal or cross the measurement of strong signal.When receiving configuration work parameter instruction
When, Step43 is executed, MCU executes configuration work parameter, and configurable parameter has ultraviolet LED light intensity, photomultiplier tube work electricity
Pressure and PGA amplification factor.After having executed above-mentioned branch instruction, Step3 will be returned to, continue waiting for the instruction of host computer reception and registration.
Sample is realized by the fluorescence intensity comparison of the titer and unknown concentration sample of different known concentrations
Measurement of concetration.The low of amplitude measurement method is arranged in such a way that photon counting method and amplitude measurement method combine in fluorescence measurement
The cutoff frequency f of bandpass filterLGreater than the cutoff frequency f of the high-pass filter of photon counting methodH, to realize a wide range of fluorescence
The continuous measurement of intensity, meanwhile, the reference voltage of the comparator in photon counting method uses the ambient noise of amplitude measurement method
It gives for twice, improves the precision and adaptability of measurement.MCU first measures the fluorescence reading of distilled water, makes an uproar as background
Twice of the reference voltage ambient noise thus of photon counting comparator is arranged in sound.MCU in sample measurement, while into
Row amplitude measurement and photon counting measurement, use amplitude measurement when big concentration, and when small concentration is measured using photon counting, middle concentration
When final measured value obtained by the weighted average of the two.Distinguish fluctuation and photon meter of the large, medium and small concentration by amplitude in amplitude measurement
The pulse spacing in measurement is counted to judge.When number of photons is considerably less in the unit time in fluorescence reaction, from impulsive quarantine circuit
The interval between pulse to come over is very big, and with the increase of the right number of photons of fluorescence, the pulse spacing becomes smaller gradually；When pulse it
Between interval less than 0.1 delicate (pulse frequency 10MHz) when, due to the presence of low-pass filter, filter between latter two pulse
It is not obviously spaced, becomes the direct current signal with ripple；When number of photons continues growing, minimum straight of ripple has been reformed into
Signal is flowed, ADC is needed to measure at this time.Due to the amplification factor and filter of configuration amplitude measurement and photon counting circuit ginseng
Number is different, so that there is an intermediate state, which can both be measured using photon counting, can also be surveyed using amplitude
Amount, realizes the continuity of large-range measuring.Fluorescence intensity calculation method such as formula (1),
Wherein, ypIt is the fluorescence intensity of Photoncounting methods measurement, yaIt is the fluorescence intensity of amplitude method measurement, y is most
Whole measured value；yaminIt is the minimum value of amplitude measurement method, ypmaxIt is the maximum value of photon counting mensuration, yaminLess than ypmax；
ωp=| yp-ypmax|,ωa=| ya-yamin| it is respectively the weight of Photoncounting methods measurement and the measurement of amplitude method.
In Allergic skin test instrument, the controller of real-time control grade is that PLC, PLC and syringe pump and fluorescence detecting system are total
With a RS485 network, PLC is that main website, syringe pump and fluorescence detecting system are two slave stations；Syringe pump uses purchase of equipment,
The upper-layer protocol of RS485 (application layer protocol) is solidificated in inside, cannot be changed.In order to guarantee to share a RS485 net
Network designs the compatible existing other RS485 communication protocols of the Allergic skin test instrument (note of RS485 communication protocol of fluorescence detecting system
Penetrate pump RS485 communication protocol), new RS485 agreement is compatible with existing RS485 application layer protocol on the application layer.
Table 1
The fluorescence detecting system RS485 communications applications layer protocol suitable for allergic reaction detector of the utility model, such as
Shown in table 1, communicated which show the data packet format of the existing RS485 application layer protocol of compatibility and with fluorescence detecting system specific
Performance data packet.Packet format is packet synchronization, starting, station address, sequence, data, end and check code, and " packet synchronizes " is fixed
ASCII character 02；" starting " is fixed ASCII code 02；" station address " is configured to 57, and fluorescence detecting system and syringe pump have not
Same station address, to identify different source data packet and destination address；" sequence " refers to the sequence number (flowing water for sending data packet every time
Number) to distinguish the data packet retransmitted when mistake；" data " are measurement data or order number；" end " is fixed ASCII
Code 03；" check code " is to obtain from " starting " to the exclusive or (XOR) " end " (including " starting " and " end ") according to position
Number.Selection communicates wireless digital representation with infusion pump applications layer to indicate fluorescence detection system in " data " of data packet
The function of system and corresponding numerical value or code, with ' L ' yy (yy is specific value), ' V ' yy and ' U ' yy respectively represents ultraviolet light intensity
Degree, PMT (multiplier) voltage and electrically amplified multiple；With '? 51 ' and '? 52 ' respectively represent read states and light intensity.To realize
The new opplication layer protocol of compatible existing RS485 agreement.
Above-described embodiment is the preferable embodiment of the utility model, but the embodiments of the present invention is not by above-mentioned
The limitation of embodiment, it is made under other any spiritual essence and principles without departing from the utility model to change, modify, replacing
In generation, simplifies combination, should be equivalent substitute mode, is included within the protection scope of the utility model.
Claims (10)
1. a kind of fluorescence detecting system suitable for anaphylactic reaction tester comprising: optical subsystem and electricity subsystem,
It is characterized in that, the optical subsystem includes ultraviolet laser light source and photomultiplier tube, and the electricity subsystem includes power supply electricity
Road and photoelectric measurement subsystem, the photoelectric measurement subsystem include uv excitation light intensity adjustment module, photoelectric current amplification mould
Block, MCU circuit and RS485 communication module, the uv excitation light intensity adjustment module output end and the ultraviolet laser light
Source connection, input terminal and the MCU circuit connection, the photoelectric current amplification module and the MCU circuit and the photoelectricity
Multiplier tube connection, the RS485 communication module and the MCU circuit connection, the power circuit are whole system power supply；
Wherein, the photoelectric current amplification module includes Current Voltage conversion and signal amplification circuit, high-pass filter and comparator
Circuit, low-pass filter and adc circuit, the fluorescence signal after allergic reaction amplify through Current Voltage conversion with signal amplification circuit
After separate two paths of signals, all the way enter the low-pass filter and adc circuit, another way enter the high-pass filter compared with
Device circuit.
2. the fluorescence detecting system according to claim 1, which is characterized in that the uv excitation light intensity adjustment module packet
Ultraviolet DAC and its isolation circuit, forward adjustable current source circuit are included, the ultraviolet DAC and its isolation circuit and the MCU circuit connect
Connect, the output end of the ultraviolet DAC is connect with the forward adjustable current source circuit, the forward adjustable current source circuit and it is described it is ultraviolet swash
Radiant connection.
3. the fluorescence detecting system according to claim 1, which is characterized in that the photoelectric current amplification module includes multiplier
DAC and its isolation circuit, adjustable photomultiplier tube high-voltage power circuit, impulsive quarantine circuit, ADC interface and its isolation circuit,
The multiplier DAC and its isolation circuit, impulsive quarantine circuit, ADC interface and its isolation circuit connect with the MCU circuit respectively
It connects, the output end of the multiplier DAC and its isolation circuit is connect with the adjustable photomultiplier tube high-voltage power circuit, described
Adjustable photomultiplier tube high-voltage power circuit output end is connect with the photomultiplier tube, the photomultiplier tube output end and institute
Current Voltage conversion is stated connect with signal amplification circuit, the Current Voltage convert and signal amplification circuit respectively with the high pass
Filter is connect with comparator circuit, low-pass filter and adc circuit, the high-pass filter and comparator circuit and the arteries and veins
Isolation circuit connection is rushed, the low-pass filter is connect with adc circuit to be connect with the ADC interface and its isolation circuit.
4. the fluorescence detecting system according to claim 1, it is characterised in that: the power circuit includes isolated buck transformation
Device, rectifying and wave-filtering, DC/DC conversion and LDO, to provide electric energy for whole system.
5. the fluorescence detecting system according to claim 2, it is characterised in that: the power circuit is divided into 4 isolated power supplies
Area, photoelectric multiplier power supply and photosignal are measured as analog power area 1, ultraviolet circuit part is analog power area 2, MCU electricity
Road is digital power area 1, RS485 telecommunication circuit is digital power area 2.
6. the fluorescence detecting system according to claim 5, which is characterized in that the analog power area 1 includes isolated buck
Transformer output, rectifying and wave-filtering, DC/DC converter, negative supply charge pump DC/DC chip and LDO circuit.
7. the fluorescence detecting system according to claim 6, which is characterized in that the analog power area 2 includes isolated buck
Transformer output, rectifying and wave-filtering, DC/DC converter and LDO circuit.
8. the fluorescence detecting system according to claim 5, which is characterized in that the digital power area 1 includes isolated buck
Transformer output, rectifying and wave-filtering, DC/DC converter and LDO circuit.
9. the fluorescence detecting system according to claim 5, which is characterized in that the digital power area 2 and digital power area 1
The output of isolated buck transformer, rectifying and wave-filtering and DC/DC converter are shared, uses DC/DC again on this basis.
10. the fluorescence detecting system according to claim 3, it is characterised in that: the adc circuit uses 24 ADS1246,
It includes and is incremented by from 1 to 128 times of 8 grades of programmable amplifier PGA, it can be achieved that strong anaphylactoid wide scope measurement according to 2 times.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820942120.7U CN208383718U (en) | 2018-06-19 | 2018-06-19 | A kind of fluorescence detecting system suitable for anaphylactic reaction tester |
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| CN201820942120.7U CN208383718U (en) | 2018-06-19 | 2018-06-19 | A kind of fluorescence detecting system suitable for anaphylactic reaction tester |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108844934A (en) * | 2018-06-19 | 2018-11-20 | 华南理工大学 | A kind of fluorescence detecting system and its measurement method suitable for anaphylactic reaction tester |
| CN109917840A (en) * | 2019-03-07 | 2019-06-21 | 浙江大学 | The output voltage regulator of photomultiplier tube high-voltage power supply special |
| EP4332637A1 (en) * | 2022-09-05 | 2024-03-06 | Institute of Radiation Medicine Chinese Academy of Medical Sciences | Signal processing system and method for radiation detector based on metal oxide semiconductor (mos) transistor |
-
2018
- 2018-06-19 CN CN201820942120.7U patent/CN208383718U/en active Active
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108844934A (en) * | 2018-06-19 | 2018-11-20 | 华南理工大学 | A kind of fluorescence detecting system and its measurement method suitable for anaphylactic reaction tester |
| CN108844934B (en) * | 2018-06-19 | 2024-03-08 | 华南理工大学 | Fluorescence detection system suitable for anaphylactic reaction tester and measurement method thereof |
| CN109917840A (en) * | 2019-03-07 | 2019-06-21 | 浙江大学 | The output voltage regulator of photomultiplier tube high-voltage power supply special |
| CN109917840B (en) * | 2019-03-07 | 2023-05-02 | 浙江大学 | Output voltage regulator of special high-voltage power supply for photomultiplier |
| EP4332637A1 (en) * | 2022-09-05 | 2024-03-06 | Institute of Radiation Medicine Chinese Academy of Medical Sciences | Signal processing system and method for radiation detector based on metal oxide semiconductor (mos) transistor |
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